Also his project 97 Hifi Preamplifier Hi-Fi Preamplifier
From scratch.
I have to say this thing is incredible
According to him this will put out 56 watts at +/-35volts into 8 ohms
BUT I used a 2x28 volt transformer +/-42volts Per Rail
And this thing is giving my Pioneer SX950 85 watts per channel some stiff competition
What is this LM3886@+/-42 volts putting out at 8 ohms (Cooling Fan)
(The Pioneer is still a Monster)
Thanx

Why not read the LM3886 app. notes and find why (not simple) a max +/-35V for 8R loads is recommended and more than that is risking damage that the thermal limiting circuits can't cope with. When the nominal speaker load impedance drops to 4R, the recommended supply limits are then reduced further to only +/- 28V.http://www.ti.com/lit/ds/symlink/lm3886.pdfhttp://www.ti.com/lit/an/snaa021b/snaa021b.pdf
Note comments in sections 4.1-2 in the second doc.

Just connecting the higher rail supplies would not pose much of a threat but when a speaker is also connected and you approach a higher than maximum rated output before clipping, the amplifier will be distorting badly, because thermal limiting will also be acting to keep the device within its SOA. It may eventually fail or not but it won't be doing what is considered safe or recommended operation. You don't actually hear any extra clean watts as by magic. The price is heavy distortion on broad signal peaks.

Maybe you like it that way or maybe you don't notice. The good news is that the difference between 68 and 85W is almost zero - you can't easily pick the difference directly other than by secondary vibrations like speaker rattles, or objects in the room. If you do hear that your amp is louder and much cleaner, a full service to the Pioneer amplifier is probably long overdue.

1) the power transistors have a saturation voltage across them, if no better data or mesurements available, 4V drop is a good (real world) estimate, so your +/- 42V now become +/- 38V peaks ... being optimistic.
2) we don't have power supply details, but no regulated one was mentioned, so I assume a regular iron transformer + diode bridge + filter capacitors raw/unregulated one is used, what 99% amps use by the way, and it will also drop, you must also substract peak to peak ripple voltage , both add to at least 20% drop, maybe higher if not generously filtered.
This would leave some 30 or 31 Vpk available, some 110/120W peak or 55/60W RMS .
In any case, the built in thermal protection will quickly turn on as soon as the case (and chip) start to heat up.

Probably no big deal in a home or Hi Fi situation, where amp may be used at , say, 10% of its power most of the time; a definite problem for DJ/PA or Musical Instrument use.

Dylon Amps, an Argentine MI amp manufacturer, had big problems because they rised supply voltages to get true 70W RMS into 8 ohms (it's datasheet rated around 50/8) and amps started muting at random times when used live, yet most worked very well on rehearsal duty.

This Amp is crystal clear and has plenty of Backbone.
Has no negative effects at all @ 42 volts.
The spec sheet says 84 volts max voltage.
I have 2 more of these transformers that are scheduled to feed some more of these LM3886's.

As long as this thing sounds as Great> as it does>>(Make that Excellent)
Plenty of Power and doesn't blow up or catch on Fire. I'm Happy.
I custom made a 12"x15" chassis made out of 1/8" aluminum and bolted the heat sink directly to it with holes drilled thru the chassis right under the heat sink, also Drilled holes all across the front of the Chassis for evacuation of accumulated heat from the transformers and the power supply(s). Cooling fan in the middle of the back Panel drawing out. I know what these chips do when they get HOT because I disconnected the cooling fan and let it get hot. It's protection circuit kicks in. It does not do that with the configuration I have. The Aluminum Chassis is also a giant heat sink its self. Also there is no evidence of the SPiKe Protection Circuitry kicking in because it would be very Audible.